#ifndef TAG_INFO_HPP
#define TAG_INFO_HPP

#include "moab/Range.hpp"
#include <string>

namespace moab
{

class SequenceManager;
class Range;
class Error;

// ! stores information about a tag
class TagInfo
{
  public:
    //! constructor
    TagInfo()
        : mDefaultValue( NULL ), mMeshValue( NULL ), mDefaultValueSize( 0 ), mMeshValueSize( 0 ), mDataSize( 0 ),
          dataType( MB_TYPE_OPAQUE )
    {
    }

    //! constructor that takes all parameters
    TagInfo( const char* name, int size, DataType type, const void* default_value, int default_value_size );

    virtual ~TagInfo();

    /**\brief Remove/clear tag data for all entities
     *
     * Remove tag values from entities.
     *
     *\param tag_delete_pending  If true, then release any global
     *          data associated with the tag in preparation for deleting
     *          the tag itself.
     *
     *\Note Invalidates tag if \c tag_delete_pending is true.  The only
     *        valid method that can be invoked that is is the destructor.
     *
     *\param seqman    Pointer to mesh entity database
     */
    virtual ErrorCode release_all_data( SequenceManager* seqman, Error* error_handler, bool tag_delete_pending ) = 0;

    //! set the name of the tag
    void set_name( const std::string& name )
    {
        mTagName = name;
    }

    //! get the name of the tag
    const std::string& get_name() const
    {
        return mTagName;
    }

    //! get length of default value
    int get_default_value_size() const
    {
        return mDefaultValueSize;
    }

    //! get the default data
    const void* get_default_value() const
    {
        return mDefaultValue;
    }

    //! compare the passed value to the default value.
    //! returns false if no default value.
    bool equals_default_value( const void* data, int size = -1 ) const;

    inline DataType get_data_type() const
    {
        return dataType;
    }

    //! get the size of the data in bytes
    int get_size() const
    {
        return mDataSize;
    }

    //! Check if variable-length tag
    bool variable_length() const
    {
        return get_size() == MB_VARIABLE_LENGTH;
    }

    static int size_from_data_type( DataType t );

    // Check that all lengths are valid multiples of the type size.
    // Returns true if all lengths are valid, false otherwise.
    bool check_valid_sizes( const int* sizes, int num_sizes ) const;

    /**\return MB_VARIABLE_LENGTH_DATA If variable_length() && lengths is NULL
     *         MB_INVALID_SIZE         If variable_length() && lengths is not
     *                                 NULL && any size is not a multiple of
     *                                 type size.
     *         MB_INVALID_SIZE         If !variable_length() && lengths is not
     *                                 NULL && any size is not the tag size.
     *         MB_SUCCESS              Otherwise.
     */
    ErrorCode validate_lengths( Error* error_handler, const int* lengths, size_t num_lengths ) const;

    virtual TagType get_storage_type() const = 0;

    /**\brief Get tag value for passed entities
     *
     * Get tag values for specified entities.
     *
     *\Note Will fail for variable-length data.
     *\param seqman Pointer to mesh entity database
     *\param entities Entity handles for which to retrieve tag data
     *\param num_entities Length of \c entities array
     *\param data Pointer to memory in which to store consecutive tag values,
     *            one for each passed entity.
     */
    virtual ErrorCode get_data( const SequenceManager* seqman,
                                Error* error_handler,
                                const EntityHandle* entities,
                                size_t num_entities,
                                void* data ) const = 0;

    /**\brief Get tag value for passed entities
     *
     * Get tag values for specified entities.
     *
     *\Note Will fail for variable-length data.
     *\param seqman Pointer to mesh entity database
     *\param entities Entity handles for which to retrieve tag data
     *\param data Pointer to memory in which to store consecutive tag values,
     *            one for each passed entity.
     */
    virtual ErrorCode get_data( const SequenceManager* seqman,
                                Error* error_handler,
                                const Range& entities,
                                void* data ) const = 0;

    /**\brief Get tag value for passed entities
     *
     * Get tag values for specified entities.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to retrieve tag data
     *\param num_entities Length of \c entities array
     *\param data_ptrs Array of pointers to tag values, one pointer
     *                 for each passed entity.
     *\param data_lengths One value for each entity specifying the
     *                length of the tag value for the corresponding
     *                entity.
     */
    virtual ErrorCode get_data( const SequenceManager* seqman,
                                Error* error_handler,
                                const EntityHandle* entities,
                                size_t num_entities,
                                const void** data_ptrs,
                                int* data_lengths ) const = 0;

    /**\brief Get tag value for passed entities
     *
     * Get tag values for specified entities.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to retrieve tag data
     *\param data_ptrs Array of pointers to tag values, one pointer
     *                 for each passed entity.
     *\param data_lengths One value for each entity specifying the
     *                length of the tag value for the corresponding
     *                entity.
     */
    virtual ErrorCode get_data( const SequenceManager* seqman,
                                Error* error_handler,
                                const Range& entities,
                                const void** data_ptrs,
                                int* data_lengths ) const = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values
     *\Note Will fail for variable-length data.
     *\param seqman Pointer to mesh entity database
     *\param entities Entity handles for which to store tag data
     *\param num_entities Length of \c entities array
     *\param data Pointer to memory holding consecutive tag values,
     *            one for each passed entity.
     */
    virtual ErrorCode set_data( SequenceManager* seqman,
                                Error* error_handler,
                                const EntityHandle* entities,
                                size_t num_entities,
                                const void* data ) = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values
     *\Note Will fail for variable-length data.
     *\param seqman Pointer to mesh entity database
     *\param entities Entity handles for which to store tag data
     *\param data Pointer to memory holding consecutive tag values,
     *            one for each passed entity.
     */
    virtual ErrorCode set_data( SequenceManager* seqman,
                                Error* error_handler,
                                const Range& entities,
                                const void* data ) = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     *\param num_entities Length of \c entities array
     *\param data_ptrs Array of pointers to tag values, one pointer
     *                 for each passed entity.
     *\param data_lengths One value for each entity specifying the
     *                length of the tag value for the corresponding
     *                entity.  Array is required for variable-length
     *                tags and is ignored for fixed-length tags.
     */
    virtual ErrorCode set_data( SequenceManager* seqman,
                                Error* error_handler,
                                const EntityHandle* entities,
                                size_t num_entities,
                                void const* const* data_ptrs,
                                const int* data_lengths ) = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     *\param data_ptrs Array of pointers to tag values, one pointer
     *                 for each passed entity.
     *\param data_lengths One value for each entity specifying the
     *                length of the tag value for the corresponding
     *                entity.  Array is required for variable-length
     *                tags and is ignored for fixed-length tags.
     */
    virtual ErrorCode set_data( SequenceManager* seqman,
                                Error* error_handler,
                                const Range& entities,
                                void const* const* data_ptrs,
                                const int* data_lengths ) = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     *\param num_entities Length of \c entities array
     *\param value_ptr Pointer to a single tag value which is to be
     *                 stored for each of the passed entities.
     *\param value_len Length of tag value in bytes.  Ignored for
     *                 fixed-length tags.  Required for variable-
     *                 length tags.
     */
    virtual ErrorCode clear_data( SequenceManager* seqman,
                                  Error* error_handler,
                                  const EntityHandle* entities,
                                  size_t num_entities,
                                  const void* value_ptr,
                                  int value_len = 0 ) = 0;

    /**\brief Set tag value for passed entities
     *
     * Store tag data or update stored tag values.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     *\param value_ptr Pointer to a single tag value which is to be
     *                 stored for each of the passed entities.
     *\param value_len Length of tag value in bytes.  Ignored for
     *                 fixed-length tags.  Required for variable-
     *                 length tags.
     */
    virtual ErrorCode clear_data( SequenceManager* seqman,
                                  Error* error_handler,
                                  const Range& entities,
                                  const void* value_ptr,
                                  int value_len = 0 ) = 0;

    /**\brief Remove/clear tag data for entities
     *
     * Remove tag values from entities.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     *\param num_entities Length of \c entities array
     */
    virtual ErrorCode remove_data( SequenceManager* seqman,
                                   Error* error_handler,
                                   const EntityHandle* entities,
                                   size_t num_entities ) = 0;

    /**\brief Remove/clear tag data for entities
     *
     * Remove tag values from entities.
     *
     *\param seqman    Pointer to mesh entity database
     *\param entities  Entity handles for which to store tag data
     */
    virtual ErrorCode remove_data( SequenceManager* seqman, Error* error_handler, const Range& entities ) = 0;

    /**\brief Access tag data via direct pointer into contiguous blocks
     *
     * Iteratively obtain direct access to contiguous blocks of tag
     * storage.  This function cannot be used with bit tags because
     * of the compressed bit storage.  This function cannot be used
     * with variable length tags because it does not provide a mechanism
     * to determine the length of the value for each entity.  This
     * function may be used with sparse tags, but if it is used, it
     * will return data for a single entity at a time.
     *
     *\param iter        As input, the first entity for which to return
     *                   data.  As output, one past the last entity for
     *                   which data was returned.
     *\param end         One past the last entity for which data is desired
     *\param data_ptr    Output: pointer to tag storage.
     *\param allocate    If true, space for this tag will be allocated, if not it wont
     *
     *\Note If this function is called for entities for which no tag value
     *      has been set, but for which a default value exists, it will
     *      force the allocation of explicit storage for each such entity
     *      even though MOAB would normally not explicitly store tag values
     *      for such entities.
     */
    virtual ErrorCode tag_iterate( SequenceManager* seqman,
                                   Error* error_handler,
                                   Range::iterator& iter,
                                   const Range::iterator& end,
                                   void*& data_ptr,
                                   bool allocate = true ) = 0;

    /**\brief Get all tagged entities
     *
     * Get the list of entities for which the a tag value has been set,
     * or a close approximation if the tag storage scheme cannot
     * accurately determine exactly which entities have explicit values.
     *
     *\param seqman   Pointer to entity storage database
     *\param output_entities Results *appended* to this range
     *\param type     Optional entity type.  If specified, search is
     *                limited to entities of specified type.
     *\param intersect Optional intersect list.  If specified,
     *                search is restricted to entities in this list.
     */
    virtual ErrorCode get_tagged_entities( const SequenceManager* seqman,
                                           Range& output_entities,
                                           EntityType type        = MBMAXTYPE,
                                           const Range* intersect = 0 ) const = 0;

    /**\brief Count all tagged entities
     *
     * Count the entities for which the a tag value has been set,
     * or a close approximation if the tag storage scheme cannot
     * accurately determine exactly which entities have explicit values.
     *
     *\param seqman   Pointer to entity storage database
     *\param output_count This is *incremented* for each detected entity.
     *\param type     Optional entity type.  If specified, search is
     *                limited to entities of specified type.
     *\param intersect Optional intersect list.  If specified,
     *                search is restricted to entities in this list.
     */
    virtual ErrorCode num_tagged_entities( const SequenceManager* seqman,
                                           size_t& output_count,
                                           EntityType type        = MBMAXTYPE,
                                           const Range* intersect = 0 ) const = 0;

    /**\brief Get all tagged entities with tag value
     *
     * Get the list of entities which have the specified tag value.
     *
     *\param seqman   Pointer to entity storage database
     *\param output_entities Results *appended* to this range
     *\param value    Pointer to tag value
     *\param value_bytes Size of tag value in bytes.
     *\param type     Optional entity type.  If specified, search is
     *                limited to entities of specified type.
     *\param intersect_entities Optional intersect list.  If specified,
     *                search is restricted to entities in this list.
     */
    virtual ErrorCode find_entities_with_value( const SequenceManager* seqman,
                                                Error* error_handler,
                                                Range& output_entities,
                                                const void* value,
                                                int value_bytes                 = 0,
                                                EntityType type                 = MBMAXTYPE,
                                                const Range* intersect_entities = 0 ) const = 0;

    /**\brief Check if entity is tagged */
    virtual bool is_tagged( const SequenceManager* seqman, EntityHandle entity ) const = 0;

    /**\brief Get memory use for tag data.
     *
     */
    virtual ErrorCode get_memory_use( const SequenceManager* seqman,
                                      unsigned long& total,
                                      unsigned long& per_entity ) const = 0;

  protected:
    unsigned long get_memory_use() const
    {
        return get_default_value_size() + get_name().size();
    }

  private:
    TagInfo( const TagInfo& copy );

    TagInfo& operator=( const TagInfo& copy );

    //! stores the default data, if any
    void* mDefaultValue;

    //! store the mesh value, if any
    void* mMeshValue;

    //! Size of mDefaultValue and mMeshValue, in bytes
    //! NOTE: These sizes differ from mDataSize in two cases:
    //!    a) Variable-length tags
    //!    b) Bit tags (where mDataSize is bits, not bytes.)
    int mDefaultValueSize, mMeshValueSize;

    //! stores the size of the data for this tag
    int mDataSize;

    //! type of tag data
    DataType dataType;

    //! stores the tag name
    std::string mTagName;
};

}  // namespace moab

#endif  // TAG_INFO_HPP
